1. They understand the shortness of life. 他们明白了人生苦短的道理。
2. The time of life is short, to spend that shortness basely, it would be too long. ----Shakespeare. 人生的时间都短促，如果把这短促的人生浪掷虚度，那就太长了。------莎士比亚。
3. Severe cases have progressed quickly (within 5 days) to a pneumonia-like illness, which involves shortness of breath and difficulty breathing. 病情严重的患者迅速发展（5天内）成类似肺炎的情况，包括呼吸短促和困难。
英英解释
n.
1. the property of being of short spatial extent
2. the condition of being short of something
3. the property of being truncated or short
4. the property of being of short temporal extent
5. the property of being shorter than average stature
6. an abrupt discourteous manner
